2.10.2 Collapse of Bridged Grain
• Grain can “bridge” across a bin, creating an empty air space below. A person can easily break through this
bridge and become trapped, risking suffocation.
• To identify bridged grain, look for a funnel shape on the surface of the grain after having removed some of
the grain. If surface is undisturbed, the grain has bridged and formed a crust.
• Never walk on the grain crust. The crust rarely becomes strong enough to support the weight of a person.
• To remove bridge, try breaking the bridge from the inspection hatch or peak. Use a pole to hit the surface,
securing it with a rope in case it is dropped. Be aware that chunks of crusted grain can move down to the au-
ger and limit flow.
Figure 2. Suffocation Hazards in Bridged Grain
2.10.3 Collapse of a Vertical Wall of Grain
• Vertical walls of grain are created when the bin is partially empty. Poking at the wall can make the grain ava-
lanche and submerge a person.
• Do not enter the bin to break down grain that has set up. Break grain mass from top of the bin outside.
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